290 THE JOURNAL OF BOTANY 
the sides at the base of the semicells subparallel and with sub- 
truncate apices, below which the sides are very faintly hollowed. 
8. Ciosrerrum Limnetioum Lemmermann in Pléner Forschungs- 
berichten, Teil 7, p. 28, t. ii. f. 89-41. This is merely one of the 
numerous forms of C. gracile Bréb. The figure given by Brébisson 
(Mém. Sciences Nat. Cherbourg, iv. 1856, t. ii. f. 45) of this widely 
distributed = is not good, and that given by Cooke (Brit. Desm. 
a very poor representation of the species. Yet, any 
one Seated & with gatherings of Desmids from one of their most 
— habitats—viz. bogs—must also be Sc aciniod with numerous 
forms of C. gracile. 
C. limneticum var. tenue Lemmermann, J. c. t. ii. f. 42-44, is not 
uncommon form of C. gracile, especialy in the eck districts 
of tropical and subtropical countri 
4, on parvuLuM Niig. var. ancustum, var.n. (Fig. 8). 
Va cellulis angustioribus. Lat. 7°7 »; apic. 94-102 p 
inter * Getantibap 
b ilmoor, near Thirsk, N. Yorks 
This variety is smaller and considerably narrower than the 
sari form. 
. Closterium idiosporum, sp. n. (Figs.6and7). C. parvum, 
thane cellulis diametro circiter 20-23-plo longioribus, dis- 
tinete sed leviter curvatis, parte mediana cellule cum marginibus 
subparallelis, grec = eradatim attenuatis et leviter curvatioribus 
b 
apices versus, apici angustissimis sed truncatis; membrana 
eng ae eee = plabes. Zygospora anguste elliptica, a vertice 
ircularis mbrana suberassa, dense scrobiculata. ong 
991-238 BS at 10-10" 5 w; lat. apie. 1-7 w; long. zygosp. 57°5 p; 
lat. zygosp. 28°7 p 
Hab. ice Fe en, Cambridgeshire 
This species is proportionately sans than C. pronum Bréb., 
the apices being much less produced and truncate. It is somewhat 
larger than C. acutum Bréb., and its apices are quite different ; 
pigs the oe is reanaiteney different from the zygospores 
of C.a m, C. cornu, ete. 
6 ROTEZNIUM NoposuM (Bail.) Lund. In Pléner Forschungs- 
See Dele “Tei 17, & net. = ts plant is recorded by Lemmermann 
as P. nodulosum (Bréb.) De Bary. 
_ 4, HEuasrrum Losutatum « Breb. in Mém. Sciences Nat. Cherbourg, 
iv. 1856, p. 124, t.i. f. 4. least E. erosum send var. notabile West 
in Journ. Roy. Micr. Soc. 1892, p. 728, t. ix. £. 17.] 
Distrib. England; Wales: ‘Foti: Treland ; ; Fra 
We have met with this plant so frequently from ree ‘Tcoalities 
in every part of the British Islands that we began to think it some- 
what strange if — weep Ae had entirely overlooked it. Latterly, 
however, we have ¢ to the conclusion that E. /obulatum, described 
by Brébisson in 1856, 1 is most decidedly the plant we have recorded 
under the name of E. erosum var. notabile. Brébisson’s description 
and figure are by no means good, but yet the outward form of the 
